In computing, network virtualization is a method used to combine hardware and software network resources and network functionality into a single, software based administrative platform, known as a virtual network. Network virtualization is achieved through software and services that allow the sharing of storage, bandwidth, applications, and other network resources. The technology utilizes a method similar to the virtualization process used to simulate virtual machines within physical computers (i.e., server virtualization). A virtual network treats all hardware and software in the network as a single collection of resources, which can be accessed regardless of physical boundaries. In simple terms, network virtualization allows each authorized user to share network resources from a single computer.
Network virtualization facilitates customization and ease of network use. Virtualization can provide customized access that allows administrators to allocate critical network services, such as bandwidth throttling and quality of service (QoS). It can also provide consolidation by allowing a multitude of physical networks to be combined into a single virtual network, allowing for streamlined and simplified management.
In the last decade, networking systems are designed such that there is a management card and multiple line cards. In these designs, management cards are seen as a master of the device, and line cards are seen as members. Networking software shares a similar design. The portion of the networking software that runs on the management card is commonly known as control plane software. Control plane software is considered the intelligence of the networking device, as its performance is directly proportional to the computer power available on the master card and bandwidth between the line cards and management card.